High-T/sub c/ superconducting coplanar waveguide filter

Coplanar waveguide (CPW) low-pass filters made of YBa/sub 2/Cu/sub 3/O/sub 7- delta / (YBCO) on LaAlO/sub 3/ substrates, with dimensions suited for integrated circuits, were fabricated and packaged. A complete filter gives a true idea of the advantages and difficulties in replacing thin-film metal with a high-temperature superconductor in a practical circuit. Measured insertion losses in liquid nitrogen were superior to the loss of a similar thin-film copper filter throughout the 0- to 9.5-GHz passband. These results demonstrate the performance of fully patterned YBCO in a practical CPW structure after sealing in a hermetic package.>